In densely packed electronic systems, heat dissipation is a big challenge due to space constraints that preclude convective thermal solutions involving blowers or fans in proximity to the heat sources. For example, avionics systems with densely packed printed board assemblies (PBA), in which conventional onboard fans/blowers are too bulky to be placed, typically rely on conductive heat sinks made of solid metal plates. However, these solid metal plates are heavy and have limited performance capability.